Why Shorter Cranks? - Part 1 - GreshFit Bike Fitting
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- čas přidán 26. 02. 2023
- If you are under 5’6” this is an important topic to understand
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Stability and balance suffer when riding cranks too long. More on that topic in my other video here: • Balance and Stability ...
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Standard mass-produced crank lengths:
175mm
172.5mm
170mm
165mm
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"Shorter" after market lengths I commonly use for riders under 5'6"
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160mm - *note this has cropped up on some recent 11 and 12 speed Shimano and SRAM
155mm
150mm
145mm - Sport
I am 4'11" and just learned my cranks are 170. THANK YOU, TIM I am so excited for my fitting this month!!
I am 5'10" switched from 172.5 to 165, felt amazing. Then I went to 160mm cranks, it was even better. I finally felt like I could get over the top of the stroke without hitching my hip.
I’m currently in this scenario: was on 172.5 for the past 10 years. Just borrowed a friends 165 cranks. Currently trying to dial in the fit but for future reference what cranks are you using that are 160? I only know of Appleman cranks which offer a wide range of length options.
Tim: Super informative and very helpful in understanding the dynamics at play when selecting the right crank arm length. I'll be revisiting my 175mm cranks now as I am seeing some of the symptoms you mention. I'm getting older and pedaling a smaller circle will likely help my hip pain and reduce rock strikes in the woods. Hope to see more of these fitting videos from you!
Totally agree with everything you've said. I'm 5'2" and now using 155/160 cranks. The bike industry doesn't care about this issue as there is very little available under 165mm. If you are considering changing to a smaller crank the difference is well worth the expense.
What a great vid mate. 166cm (5’5.5” in old money) I’ve always used 170mm cranks. I always felt odd when climbing, like I’m riding a camel and I struggled to keep a higher cadence than about 85. Having watched this and various other vids a lightbulb just went off in my head. 💡😳🤔😎👍🏻
I’m now going to try 165mm’s.
Thanks mate.
Blessings from England.
Thank you, sir! I’m sure you will love the 165s. I’m happy that these videos are making an impact greater than my little fit studio :). Best of luck to you - enjoy every ride !
Tim, great video! I couldn't agree more! Moving from 175mm cranks to 170mm cranks on all of my bikes has had a profoundly positive effect on my riding and post-ride recovery!
Added bonus is better handling and less pedal strikes when on the mtb!
Great stuff!!
Pedal strikes that's the reason i switched running 160, lots of trials and hill.
Fascinating. I have a couple of bikes with 175 standard crank length and always thought they were reasonably comfortable. Then recently got into restoring old bikes and finished a Phillips 26" three speed made in 1967. It's cranks have a length of 16 cm which I guess is a '160', '165'? (there is only a "V" stamped on the crank, no numbers). Riding this bike, I found my cadence had increased (especially since there are only 3 gears to choose from) but the bike is more comfortable to ride even with saddle height set the same as my other, more modern bikes.
I'm 170 cm (76 of inseam) and have been riding 160 mm cranks for 2 years after a life on 170s. I switched to oval rings at the same time, so can't say for sure the effects individually, but very happy with the change.
Excellent!!
how much saddle height did you increase?
I found a Dura ace 167.5 absolutely love it. Went from 172.5 to 170 to this 167.5 DA.
Great to hear! ENJOY EVERY RIDE
A good method of knowing what is good for you is what I recommend.
Take your seat tube hight to crank length and multiply your 18% for flat rides and 19% for climbing rides.
I'm 5,8 and I have short femurs therefore I use 150mm for all around and I use 155mm for my road bike.
I was thinking, I'm 6' 1", no way I want a shorter crank. Glad the explanation early on didn't make me feel like an luddite outsider, again.
So as it happen some years ago, my wife being petite at 4'9", proportional for her height and rides 44cm/650c bike. Right off it was difficult for her on the standard 165 cranks that came on her bike. She suffered from some of issues you stated. Hip angle was out the window. To dial in her fit, finally settled on 145s. Which was perfect. No more issues. Crank lengths aside, the sad thing is that still as of today, short riders are even less of a consideration than when she got her bike years ago. No off the shelf 650c frame (unless custom) options to properly fit short riders around her height.
Just to let you know. All Canyon road frames smaller than XS now come standard with 650b wheels. Hope this helps. 😉😎👍🏻
I'm 5'6' and I like 165mm, I even have some 152mm that feel just as good.
I'm 6'2" with long legs. Tried 170s instead of 175s and hated it. It felt like riding a child's bike to me and I was noticeably slower and it felt worse when getting out of the saddle on steep inclines. Pedalling while standing in general felt weird as I just felt like I just didn't have the leverage and couldn't put the torque I was used to through the crank. I went back to 175 and was immediately faster. Not looking back. I think it's a very individual thing - obviously.
Agreed - very individual. Out of curiosity how many miles / rides did you complete with the 170s?
@@greshfit I think four rides and a total of 300km. Not that much I’ll admit. The feeling when pedalling seated did improve. But pedalling out of the saddle I just could not get used to. My inseam is 91cm / almost 36 inches. I feel restricted in movement with shorter cranks. Never had an issue with hip angle despite a very low front end and long cranks, either.
FYI I have a buddy same height as you, long legs, went to 170 and loves it. Got rid of his knee pain.
Yes i went from 175s to 170 as i had a takeoff from an old bike. Its on an mtb daily but i am a roadie from 4 decades. Strange at first but an improvement and certain knee issues ceased. Also at 5' 10" with a 30" waist i moved my feet closer together via spd cleats about a 1/16" and one was slightly too far forward. A definite change in the flywheel for the better, rpms noticeably up and feel less fatigued.
👍 enjoy ! Personally I ride 165s and love them - 5’9” 34 inch inseam
As a short rider 5'4" 27" inside leg. 170 or 175mm is usually all I get offered even on a small ,xs or even xxs which is ridiculous. Having a single speed / fix with 165mm cranks I could see this was a big improvement.
However 165mm still felt too big . So having a on off relationship with bikes since a kid I'm now 61 I put together a bike from a few old bikes using 140mm cranks from a cheap folding bike I thought this would be to short?
No this is a revelation, I can now enjoy biking in my later years . If I am honest 150mm might be the sweet spot if I can get hold of such a thing but for now this is working great . My friend who helped me build and is 6' tall gave it a go and he didn't think it was outrageous short he thought it was doable even at 6' .
So seeing bike fitters like yourself with the move to shorter cranks has been a long time coming ,thanks for your efforts. I am just a casual rider but finding short cranks and all the science has given me renewed joy in biking again, thanks. Greetings from Scotland.
I loved reading this, thank you for the comment! Very happy tohear you found success giving it a go. It’s funny and also sad to me how much this topic has been ignored when really, its implications are quite significant
Regarding 150 - those can be found from a company called speedandcomfort by John Cobb
speedandcomfort.com/collections/short-cranksets-bike-components
This is their second generation crank. However, they did also make a first generation which used sram GXP spindle standard. Some of those are still floating around on eBay. They were designed more around the 10 speed spacing.
The second GEN listed on the website is working really well on 11 and 12 speed bikes and has 24mm spindle so seamless installation on Shimano Hollow tech II bikes
Best of luck from Pennsylvania!
@@greshfit Thanks for your reply, i really do appreciate your time, input and efforts.
I’ve benefited from using a 155 crank based on inseam height of 72cm and would probably consider a road bike if Shimano decided to make shorter cranks cater to shorter cyclists below 165mm height.
Bike frame sizes are widely available for shorter cyclists but the crank sizes from Duraace or Ultegra are not ideal. There are also 2 types of crank cater to MTB (bended arms) & Road Bike (straight arms).
Great info!! Thanks!!!
You bet!
Please like, subscribe, and share 🙏
The same thing here, 5'10. I spent $20 total drilling, re-threading, and cutting my 175mm to 155mm. ZERROO pedal strokes reached. Simple to clime.
175mm cranks are NOT necessary for mount bikes-absolutely not.
Awesome. Would be interested to see how you did that mod
5’4” all 4 bikes 170mm crank! Tried 165mm and hated it! My rpm is perfect. I climb like a mountain goat. Saddle is perfect. Leg length v torso length is more important than overall height.
Much more of a complex topic than your description
Agree leg length is important
I'm 71 and 5'4". I have been riding 170 cranks for years. But last year I got 150's from Jcob. Having had saddle issues forever, these cranks resolved that problem almost immediately. It's also much easier to maintain cadence. The sweet spot for me is 90-92 and that wasn't always easy to do with the 170's. I'm actually quite surprised when I look at my scree and see cadence is 94 or 96. Seems easy to maintain those kinds of rhythms.
If you haven't tried shorter cranks, don't knock them.
Where did you buy those 150mm crank arms?
Right here: speedandcomfort.com/collections/short-cranksets
I'm 5'8 - 30inches inseams - long torso short legs - poor hamstring flexibility. Been running 170mm cranks for years, thinking of trying 155 to open up the hip angle and improve saddle comfort after this video. Thanks.
Good luck!
i assume it also relates to the age as well. After 35, the flexibility is getting less. I just changed to 165mm resulting a stable hip on the saddle.
Shouldn't crank length be determined by your inseam & not your height? Inseam length actually varies a lot for people of the same height. On second thought, would thigh length be even better?
Great thought !
That's what I was wondering. Is there a correlation between leg length or femur length and optimal crank length? Tim, you might have to use that white board to derive some equations😂
DubC ? wow. Just came across your page, heard you say West Chester and immediately hit subscribe. I was born in DubC, living bin Colorado but still have plenty of family living there .... Building a new dirt jumper( Kona Shonky) and a new slope style bike Canyon 720)was thinkin 155's but wanted to do some research first also looking to switch out the cranks on my 2023 Commenciasl Meta sx V5 and my 2023 Commencial FRS but was thinkin 165's for poundin better legs . Meta has a dropper obviously where as the FRS is always dropoped as low as my inner knee at full stand. The FRS is more my question due to needing to gettin with it when need to pedal takes place for bursts to prevent inevitable doom. Same would apply to my hardtail dirt jumper and my slope style bike but maybe you could pick it apart man. I woukld be more thasn happy to shoot you a call and pay what ever you charge for 5 bikes but all for different styles of riding. I am looking to finish my new dirt jumper in the next week or two , new slope style bike has not been released yet so have about a month for it. The FRS is for the" nasty nasty" and take off type air and drops, I was trying to roll out to moab in the next three weeks but last check they had snow on the ground. Basically would love to pick yourt brain regarding getting the most leg out of the freestyle bikes and relaxed leg for my sunday drives down hill. Cotton
Cool to hear that !
Shoot me an email on this - tim@GreshFit.com
Thanks!
You bet!
Nice video!
Where can I buy those smaller crank arms that are compatible with Shimano?
Thank you! Check the video description - I put part numbers there... you will need to google those and see who has them online. Or bring those number to your LBS and see what they can do. Note that if you have 11 speed you are best off getting a 12 speed shimano crankset which are very readily available.
I'm curious where you tend to place riders that are a little taller or at least around 5'11" - 6'0" and above? Do you still tend to go shorter, around 165mm, or are "conventional" sizes such as 170 or 172.5mm usually fine for these riders?
Generally I go with 170s for these riders. But i'll need to stress that's a general rule... it comes down to how well a rider can remain stable in the saddle at load... Ultimately the best way to land on a size it seeing a good direct observation fitting to help make this call.
Leg length also comes in. 6 foot tall rider with short legs and long toros may need 165 for the same reason a 5'7" rider does who has the same leg length at 6' tall rider
Hope that helps! When in doubt go with 165s on the cheap and give it a month. See what happens. It won't hurt you and more likely will be something you'll like
Has anyone ever done a power meter test with different crank lengths? Seems you can spin faster with shorter cranks and less circumference distance per revolution however with a shorter moment arm can you put down the same power and cycling speed as a longer crank arm. Seems like a trade-off and not sure which is actually better for bike racing performance. I definitely agree a longer crank arm or too long a crank arm could end up causing a less stable ride in the saddle. I actually have a bike with 172.5mm crank arms and another with 170mm. Not certain which one I like better - although the difference is pretty small at only 2.5mm.
I find that if making a change - 2.5mm isn’t enough to make much difference. 5-10mm change in length is a better route
I am curious about smaller or not but I always rode 170mm and want to ride same size that can manage from 30yo until I cycle into my grave, looking SRAM red axs etap on next bike, just got 54cm frame size as only one left compare to 56cm I used before, I have to work out stem length to manage to hold drops of can too
High rpm? I often cycle at 75-85rpm but unsure if go higher since my issue is I love the pressure on my feet or I feel I'm too slow
In perfect world, we could experiment with crank length in a bike shop, and then order what we like. Unfortunately, this is not the case so if you are curious, and like the thought of riding more stable than it may be worth giving 165 a try, the odds are greater that you will Like it then not. Good luck, sir!
I've been thinking about going to shorter cranks, but my powermeters are crank based, and that would add even more to the cost…
(184 cm / 175 mm)
Yeah, that’s a tough one. One suggestion I like to give in these scenarios is, if you have a secondary bike, find an inexpensive shorter crank giving it a whirl on the cheap. If it makes a big difference for you, then you will feel confident that it’s worth the investment doing it to the power meter bike. Good luck and happy riding!
A friend of mine is not a bike fitter but two times masters world champion on road he has chosen the opposite with a height of 178cm and rather short legs he is using 180mm - thus there are many factors- may the fact that he was Olympic speed skater makes a difference
I’m only 5ft and finding a bike that is the correct frame size was really difficult, now that I’m getting into tris I’m looking at your cranks to swap mine. I have a felt vr 105 advanced in a 43 and they use a 165 crank. Will a 145 totally throw off my bike fit?
At your height, that should work really well. 165 is the shortest industry standard but that’s an outdated. Get these: speedandcomfort.com/collections/short-cranksets-bike-components/products/copy-of-alloy-24mm-short-crankset-145mm
They are on backordered, but I think you can get one reserved. Alternative to this would be rotor but that will be around 700.
Have a question, race bmx so trying to find something that fits my use is next to impossible. Built a bike earlier this year, and put 175 on it due to that’s what old bike had and what I got told to put on it. But feel/think they are on the longer side and when I was building the bike I questioned if I should go smaller since 175s were on my old bike and felt too big. My in seam is 25.6” or 65cm, height 5’4. Which just having a hard time figuring out where a good starting point would be. Don’t really jump yet, and don’t plan on jumping a whole lot. Also thanks for making a video more focused on us shorter guys
I think 160 would be a starting point. Good luck!
What is the ideal chainrings on 165mm crank arm. Im thinking to use 52/36. Thanks
Great question.... to be honest i'm indifferent on this... I don't necessary think you need to change rings when changing crank length. I'd suggest going with what makes sense for you fitness level and terrain. Hope that helps!
I am absolutely crazy last year. My saddle height is 83cm. I have really long legs. But as junior and U23 i was riding 175 mm...then I moved to 172.5...now, 20 years later i hear more and more about shorter cranks. Would you say 170mm is enough to go shorter? I have no option to try multiple. I will need to buy of course. I am just affraid i will have less power with shorter crank (like when you are undoing old screw, you use longer leaver). Thanks!
If you are not racing I’d recommend going for 165
Do you have some rule of thumb or formula for size of crank. 66/67 inches tall & 29 inch in seem.
No
I learned something new here. I definitely need shorter cranks on all my bikes.
Right on
I run 165s and I ride a 54 frame. Did it to raise the seat a bit and get lower on the front end.
Great application!
@@greshfitI'm also on 165mm cranks on the advice of my fitter but considering the new 160mm for the Shimano 12s groupset.. any reason to not go down even lower?
@@JohnAlzagatiti hard to stay without seeing you but overall i'd say there's no harm going the next size down if it's available to you. Shorter cranks just about always make the pelvis more stable and that's never a bad thing! Good luck !
What can you say about the cadence and torque differences on standard vs shorter crank length? Shorter crank always needs more torque to compensate for the lesser leverage of the arm, correct? (Assuming the gearing ratio is the same across the board)
Good thought..... I don't have much to add here. I look at crank length as a means to improving pelvic stability when a rider is unable (because of height or function) to stay stable. From there the body will adapt to shorter cranks and perform better than before.
I have the standard 172.5 on my size 54. I'm considering going to 168. I'm 5'8".
Go for it!
Thankfully shimano now offering 160 for 105 and ultegra cranks
Yes 🙌
Does the length of the cranks corospond to the size of the frame riden?
No
Hi Gresh, what crank length do you think I should get, I am 160cm, 72cm inseam. I am currently on a 170mm crankset
155mm or 150mm
@@greshfit Thanks! Gresh, I've been riding on 170mm cranks for about a year since I started cycling and yesterday, I was fortunate enough to try a bike fitted with 165mm cranks. Tested it for about a hundred meters at an extremely slow pace and it felt extremely weird almost like I was riding a kids bike. After testing the 165mm cranks, I was skeptical on changing my crankset to anything lower than 165mm but after watching so many videos, I am really not sure. Here in my country, 150/155mm cranks are almost impossible to find. I am deciding between the 160 or 165mm cranks but am not sure if I should settle for the 160mm as the 165mm felt super weird. I am looking for long term performance and power efficiency. Which would you kindly recommend for my height of 160cm and inseam of 72cm?
I’d say 160. It will take around a month of regular riding for shorter cranks to settle in
@@greshfit Alright, thanks very much Gresh! Liked your vid and subscribed!
Thank you 🙏
crank length is in function of leg length, everything else is subjective, do you have any calculation about your claim, i have mtb with 172.5 and it is good for climb because pedal rpm is in function of speed so for lower speed lower pedal rpm because mass momentum, on road bike is 170 and it is good for fast speed and pedal rpm(i had 172.5 and it was no good)
I’m not sure what your question is here, sir
What are some smaller cran brands people can use for scram dub
Brands would be Speed and Comfort by John Cobb (aka JCob) or ROTOR cranks. I'm not aware of either having a DUB option - but you can replace your DUB bb to work with these cranks. Hope that helps!
Interesting. I am 188 cm tall (6'2"), but have a relatively long torso and thus my preferred jeans length is at 33".
I have been riding on 175 mm cranks for years and thought of getting shorter crank arms from time to time, since I always felt they had a 'dead pedalling area' but so far I have never done anything about it. Having seen this video pushes me in wanting to make experiments on this for a better riding style - and who knows; maybe even get rid of some minor, but annoying and constant, back and knee pain?
Go for it !
Hello guys! I'm 174cm and used 170mm cranks so far. My legs are short, so I knew this is too long for me. I have a "new" bike with a 175mm crank and oh God it definitely feels more exhausting to pedal it. It feels I have to bring my knees to my chin to complete the pedal stroke. The only problem I have that here in Hungary there are very few of the 165mm cranks and can not find any shorter. These "short" cranks are tipically in the higher end of the palette with a ridiculous pricetag I can not afford. Furthermore for the older 3x drivetrains there are no shorter than the 170mm. For the newer drivetrains it is not only cost more than twice than the entire bike, but I have to change all the drivetrain to be able to accommodate the 165mm cranks, so the price would go even higher. Buying a newer, but lower end bike still costs a whole fortune and have basic acera or alivio components which have also the 170mm for the shortest crank. Are there any recommendations what should I search for to find any more budget friendly options? Thanks!
Hi there! I am sorry, but nothing comes to mind as I am based in United States, and don’t have enough context to really advise. That said, based off of your comment what I might advise, is building up a bike custom from ground up - be creative as you can, it does not seem like chances of success will happen, doing it the other way around if that makes sense. Good luck!
fitkitsystems.com/product/crank-arm-shortener/
Additionally, there are creative things like this, an adapter. Also, perhaps a machinist that you can find willing to drill into your current cranks to make them shorter
@@greshfit Thank you for your answers!
Im 5'4ft tall... Im planning to use 165mm? Is that good?
Without seeing you i'd say sure, 165 is good. 160 would likely also be good. Your call
So my next time on a shop I need to see a bike fitter first?
My personal advise for anybody looking for a new bike is to make an appointment with a bike fitter to see what bikes are the most geometrically compatible by using a fit bike that can replicate a given bike's geometry. I've only served a tiny handful of customers that did take this approach.
Shimano DuraAce Di2 12-speed 160mm 😎👍👍 …49 frame Roadbike…
Nice 👍
You forgot 167.5mm made by Shimano...
Yep I did ! I will admit, intentionally as they are so uncommon
Shorter crank = less leverage. Also shorter crank = higher saddle and tippy toes getting to the floor.
Agree except last part
SHORTER KRANK is better....hmmmm....some will say the right height of the saddle for more stability and you are saying shorter krank....crazy
for me i don't think that a shorter krank will perform better on a long climb....i will say having a short ride a short krank might be good but not for long ride...
conclusion i don't agree with you??
Try it for a month and see
This is rediculous.
Why
The only reason to go to shorter cranks is because youve lost flexibility and "need" to. Try focusing more on stretching post ride and learning how to undo the shorter muscles youve built by getting stronger. The only reason the pros have switched to shorter cranks is to allow them to ride in a lower more aero position because aero at the speeds they go is a more powerful determinate of speed than the loss of power at the pedal via shorter cranks. Unfortunately this shorter length fad doesnt translate over to us sub 25mph riders........and in the long run you are just shortening your pedal stroke and muscle range.
lol